Brush holder assembly for electric motors



E. c. KLEBE, JR 3,436,576 BI USH HOLDER ASSEMBLYFOR ELECTRIC MOTORS Filed Sept. 196a April 1, 1969 Sheet fz INVENTOR. 1 n wmvEss Elmer C Klebe J A ORNEY April 1, 1969 E. c. KLEBE. JR 3,436,576

HOLDER ASSEMBLY FOR ELECTRIC MOTORS Fi1edSe pt.5.1965 Sheet 3 012 INVENTOR.

. WITNESS Elmer C. Klebe Jr.

ATTORNEY United States Patent U.S. Cl. 310-239 2 Claims ABSTRACT OF THE DISCLOSURE A brush holder assembly for an electric motor including a seat formed in the motor frame, which seat is designed to accept a brush holder tube, and clamping rings to hold the tube in place on the seat.

This invention relates to electric motors and more particularly to an improved carbon brush holder assembly designed to become part of an electric motor.

An object of the present invention is to provide improved support structure for a brush holder and brush in the end bell of an electric motor.

Another object of this invention is to provide a brush holder assembly the improved construction of which facilitates removal or installation of the brush.

A further object of the present invention is to provide a brush holder assembly having a compact and relatively uncomplicated design that results in a reduction in the cost of manufacture.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiments of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, con struction and advantages of it when read in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view, in section, of the brush holder assembly of the present invention,

FIG. 2 is an exploded perspective view of the brush holder assembly shown in FIG. 1,

FIG. 3 is a perspective view, in section, of another embodiment of the brush holder assembly of the present invention, and

FIG. 4 is an exploded perspective view of the brush holder assembly shown in FIG. 3.

The carbon brush holder assembly of the present invention may be utilized with an electric motor such as that illustrated and described in United States Patent No. 3,177,388, issued on Apr. 6, 1965, to Albert Norman Cook.

Referring now more in detail to the drawings, wherein similar reference numerals identify corresponding parts throughout the several views, represents a brush holder assembly substantially as shown.

As illustrated in FIGS. 1 and 2, a conventional carbon brush assembly includes a carbon brush 14 equipped with a wire lead or pigtail 16 surrounded by a helical compression spring 20, one end of the pigtail being connected to the brush and the other end to a metallic clip 18-, all of which are received in a brush tube 22 having a lug 24.

A substantially cylindrical brush holder 28 constructed of any suitable insulating material, such as plastic, has formed therein a recess 32, adapted to receive the brush tube 22. The brush holder 28 includes an outer cylindrical surface 36 divided into an upper surface 38 and a lower surface 40. The upper surface 38 has formed thereon a pair of opposite hand stepped flanges 42 which ex- 3,436,576 Patented Apr. 1, 1969 tend around the periphery of the upper surface 38 and are spaced axially of each other along the [brush holder 28. Each flange 42 is divided into two parts forming coterminous steps 43 and 44 with the former step 43 extending radially of the brush holder 28 a short distance further than the latter step 44. Each step 44 includes a face 45 and each step 43 includes a side wall or abutment 47 extending at right angles to the corresponding face 45 of the step 44. The side walls 47 face in opposite directions axially of the brush holder 28.

A portion 48 of the rim of a brush supporting electric motor end bell includes integrally formed therewith an elongated substantially semicylindrical sleeve 49 which serves as a seat for the brush holder 28, having an inner surface 50 and an outer surface 51. The inner surface 50 includes a depressed central portion 52 and a pair of raised end portions 54. The outer surface 51 of the sleeve 49 includes a pair of axially spaced ring grooves 56 extending around the periphery of the outer surface one near each end of the sleeve 49. The ring grooves 56 includes a floor 58 and the sleeve 49 includes a pair of axially extending flat end faces 61.

Assembling the brush holder assembly 10 requires loading the carbon brush 14, pigtail v16, metallic clip 18 and helical compression spring 20, into the brush tube 22, sliding the loaded tube 22 into the recess 32 in the brush holder 28 and setting the brush holder in the sleeve '49 so that the lower surface 40 of the holder rests on the pair of raised end portions 54 of the inner surface 50 with the ends of the steps 43 and 44 abutting the fiat end faces 61 of the sleeve 49. Finally, the brush tube holder 28 is adjusted axially of the sleeve 49 to align the steps 44 with the corresponding ring grooves 56. At this point it is noted that the thickness of the steps 44 corresponds to the thickness of the sleeve 49 at the point measured between the floors 58 of the ring grooves 56 and the inner surface of the raised end portion 54. Thus, in the final assembly step when a pair of open round snap rings 60 are slipped onto the brush holder 28 and the sleeve 49, each ring will seat on a surface, formed by the floor 58 of the grooves 56 and the face 45 of the step 44, that is symmetrical and provides a snug fit for the snap rings.

With the snap rings 60 in their operative positions the brush holder 28 is locked against endwise movement relatively to the sleeve 49 because a portion of the snap rings 60 is captured by the grooves 56 and the other portion of the rings 60 seats on the face 45 of the steps 44 and adjacent the side wall 47 of the steps 43. Rotary movement of the brush holder 28 relatively to the sleeve 49 is prevented by the abutment of the ends or lips of the steps 43 and 44 against the flat end faces 61 of the sleeve 49.

Turning now to a description of another embodiment of this invention, illustrated by FIGS. 3 and 4, a brush holder assembly 12 includes the brush tube 22 which tube is adapted to receive a brush, pigtail, compression spring, and clip in the same manner as the embodiment illustrated in FIGS. 1 and 2.

A substantially cylindrical brush holder 62 constructed of any suitable electrically insulating material, such as plastic, includes a recess 64 adapted to receive the brush tube 22. The brush holder 62 includes an upper portion 66 and a lower portion 68. The upper portion 66 while concentric with the lower portion 68 has a larger diameter and terminates in overhanging lips 70 and 71 which lips extend the length of the brush holder. The upper portion 66 includes a pair of slots 76, having sides or abutments 76', cut into the periphery of the upper portion which slots extend from the lip 70 on one side to the lip 71 on the other side. The lower portion 68 includes a peripheral positioning flange 78 which flange is formed on the outer surface of the lower portion and extends from the lip 70 on one side to the lip 71 on the other side. The flange 78 3 is centrally located axially of the brush holder 62 and has a depth equal to the Width of the lip 70 or 71.

An elongated substantially semicylindrical sleeve 80 is integrally formed with the rim portion 48 of a brush supporting end bell. The sleeve 88 is substantially equal in length to the brush holder 62. The sleeve 88 includes flat faces 82 and 84 which extend the length of the sleeve and are equal in width to lips 70 and 71. The slave 88 also includes an inner surface 86 and an outer surface 88. The inner surface 86 has formed therein a peripheral groove 90 that is centrally positioned axially of the sleeve 80 and is equal in depth to the depth of the flange 78. The outer surface 88 includes a pair of axially spaced peripheral slots 92.

The brush holder assembly 12 is assembled by loading the brush tube 22 as in the embodiment described above, sliding the loaded tube into the recess 64 of the brush holder 62 and then seating the holder in the sleeve 80. With the brush holder 62 properly seated, the flange 78 mates with the peripheral groove 90 thereby to center the holder axially of the sleeve 80 and help prevent endwise movement of the holder in the sleeve. In this position, the fiat faces of the overhanging lips 70 and 71 engage the fiat faces 82 and 84 of the sleeve 80 in abutting relationship and the slots 76 of the brush holder 62 align with the corresponding slots 92 of the sleeve 80. Thus, rotary movement of the brush holder 62 in the sleeve 80 is prevented by the abutment of the lips 70 and 71 with the faces 82 and 84, respectively. A pair of clamping rings 94 are adapted to fit snugly around the holder 62 and the sleeve 80 within the aligned slots 76 and 92 and serve to clamp the holder to the sleeve and further restrain the holder against endwise movement relatively to the sleeve.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to preferred embodiments of my invention which are for the purpose of illustration and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.

Having thus described the nature of the invention, what I claim herein is:

1. A brush holder assembly comprising in combination a frame part of an electric motor and an insulating brush holder tube mounted on said frame part; said frame part having a semicylindrical elongated seat provided with face portions and said semicylindrical elongated seat being adapted to receive said brush holder tube, the external surface of said semicylindrical elongated seat being formed adjacent to its opposite ends with grooves; said grooves extending along said external surface in parallel planes that extend transversely of the length of said semicylindrical elongated seat, said brush holder tube having a lower portion semicylindrical in shape so as to fit into said open seat, and said brush holder tube being formed on its upper portion with abutments having edges registering with portions of the grooves in said semicylindrical elongated seat and having lips engaging the face portions of said semicylindrical elongated seat when said brush holder tube is set in said semicylindrical elongated seat; and clamping rings disposed in the grooves of said semicylindrical elongated seat and engaging the abutments formed on the upper portion of said brush holder tube.

2. A brush holder assembly comprising in combination a frame part of an electric motor, and an insulating brush holder tube mounted on said frame part; said brush holder tube having an upper portion and overhanging lips formed on the upper portion, said frame part having an elongated open seat, said seat being provided with face portions and formed with a depression, the overhanging lips having faces that engage the face portions of said elongated open seat when the brush holder tube is set in said elongated seat, the external surface of said elongated seat being formed adjacent to its opposite ends with grooves; said brush holder tube having a lower portion fitting into said open seat, and also having a flange for entering the depression formed in the open seat, and said brush holder tube having an upper portion formed with grooves adjacent said brush holder tube opposite ends, the grooves in the external surface of said elongated seat registering with the corresponding grooves in the upper portion of said brush holder tube when said brush holder tube is set in said elongated seat; and clamping rings located in the grooves of said elongated seat and the grooves of said brush holder tube.

References Cited UNITED STATES PATENTS 3,162,782 12/1964 Downs 310-50 3,177,388 4/1965 Cook 310-247 3,329,844 7/1967 Happe 310-239 ORIS L. RADER, Primary Examiner.

GUS NUNEZ, Assistant Examiner.

US. Cl. X.R. 

